While recalling that "there is not a lot to like about Labour, seen from the outside" – a view with which I concur – Polly persists in the absurd Labourite delusion that Clegg committed some kind of betrayal of Labour. Her fantasy that the Lib Dems are "in deep trouble" is her comfort blanket.

There is an understandably a certain apprehension among Liberal Democrats. But we know we took the only feasible option in May, we are proud of our achievements so far, and we are grown-up enough not to throw our toys out of the pram because we can't have even more chocolate.

Sarah Ludford MEP

Liberal Democrat, London

• You report that the coalition government plans to raise an extra £7bn by 2015 by tackling tax evasion and fraud (Alexander targets the tax dodgers and promises pain will be shared, 20 September). Such poverty of ambition will perpetuate the poverty of working people. The UK financial crisis is caused by a collapse in national income, and this government is determined to make the poorest fill the gap by cuts in pay, redundancies and reduced services.

They have asked the billionaire Sir Philip Green to advise on "public savings". HMRC estimates unpaid and late-paid tax alone amounts to at least £26bn annually, and the tax lost through evasion and avoidance could be four times that. Yet, as part of the threatened austerity measures, the government will continue cutting the number of HMRC staff (26,000 since 2005), a foolish policy when each frontline tax officer brings in 30 times their salary on average. Perhaps Mr Alexander could develop a more aggressive policy, using the tax knowledge of Sir Philip and his Monaco-based wife.

George McLean

Manchester

• Simon Clarke (Letters, 20 September) is right about Catholicism, including its agreement with Islam's condemnation of the further ascendancy of the money-grubbers in our society. As an atheist, if I had to choose either Rome or conservatism, I'd choose Rome. It would be good to have a third choice, for the humanity that has always been the morality of the Left. Its principle is that the right thing is always the rational means to the end of getting and keeping people out of bad lives (defined in terms of deprivation of living-time, bodily wellbeing, freedom and power, the goods of relationship, respect and self-respect, and the goods of culture). There used to be liberal leaders who knew that, and thus had more than the morality of our political class.

Ted Honderich

Grote professor emeritus, philosophy of mind and logic, University College London

•Simon Hoggart said of this year's Lib Dem conference: "It's not helped by the vast black auditorium at the [new] Liverpool ACC, which digests emotion like a sperm whale swallowing plankton." Contrast what Michael Heseltine said on the BBC in 1988 about the Winter Gardens, Blackpool: "There is nothing like it: the feeling of the audience in that building, tiered up there, towering over you. And you can see them there, rank upon rank of them … whereas in these new buildings the hall, the carpeting and the chairs, it's all been toned down to remove the excess of language or of tone. You have to fight, really fight, to try and get through to the audience."

The Winter Gardens Pavilion was built in 1897 by architects Wylson and Young, rivalling Frank Matcham, who built two other fine Blackpool auditoriums. Why can't modern architects understand how energy is transmitted? There must be ways to inject life into the bland, acoustically flat conference venues that all three party conferences now favour.